Improvement in casting hollow cylinders



J. W. BRITTIN.

` Casting Hollow Cylinders. No. 99,144.

Patented Jan. 25,1870.

N. PEYER PmlufLimugmpher. washington. D. C.

UNITED STATES PATENT OFFICE.

JOHN W. BRITTIN, OF BLACK ROCK, CONNECTICUT.

IMPROVEMENT IN CASTING HOLLOW CYLINDERS.

Specification forming part of Letters Patent No. 99,144, dated January 25, 1870.'

To all 'whom vit may concern.'

Be it known that I, JOHN W. BRITTIN, ot' Black Rock, in thc county of Fairfield and State of Connecticut, have invented anew-and useful Improvement in Casting Hollow Cylinders; and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference being had to l the accompanying drawings, forming part of this specification, in which drawings- Figure l is a vertical central section of this invention. Fig. 2 is a horizontal section of the same.

Similar letters indicate corresponding parts.

This invention consists in the arrangement ofa hollow perforated core passing through the mold in such a manner that the fluid metal can be introduced through said hollow core, and that by the supply of metal kept in said hollow core a sinking head is produced, from which the shrinkage in the hollow cylinder to be cast will be filled up.

In carrying out my invention I construct a hollow core, A, provided with apertures a at its bottom and at certain intervals between the bottom and top of the intended casting, said apertures being sufficiently large to allow the metal to flow readily through them. This core is placed in the flask or mold B, and it is kept in place by a stop, b, at its bottom, which drops into a socket in the bottom of the mold, and by a bridge, c, on the top of the mold, or by anyother suitable means. The metal is poured into the hollow core, and it passes through the apertures a into the mold until said mold is filled, and an additional supply of fluid metal or a sinking head is formed by the metal contained in that portion of the core which projects beyond the mold.

It is obvious that the metal will remain tluid longest in the central part of the casting, and as it cools and shrinks in the mold a supply of iluid metal will pass down from the sinking head in the core to till up the shrinkage.

In the upper part of the mold I make suitableperforations, d, to permit the escape ot air, and these openings also may serve as an escape for the dross of certain metals, such as lead, so that such dross will be separated automatically' from the casting formed in the mold. It" desired, the head of the ask maybe provided with a rim to form a receptacle for the dross.

`In this way I am enabled to make a sound casting, as the unsound parts will be found within the core or sinking head and the dross will be forced out through the openings in the top of the mold.

What I claim as new, and desire `to secure by Letters Patent, is-

The hollow core A, in combination with the mold within which it is placed, substantially as shown and described.

JOHN W. BRITTIN.

Witnesses:

W. HAUEF, E. F. KASTENHUBER. 

